Combining H-alpha and Ca K-line solar images

Imaging was done with a CaK PST, a Solarmax II, BF15, H-alpha scope and a DMK  31AU03.AS CCD camera, mounted on a Celestron AVX mount.

The data were captured as SER files with AstroDMx Capture.

Click on an image to get a closer view

Screenshot of AstroDMx Capture saving a SER file of Ca K-line solar data

Screenshot of AstroDMx Capture saving a SER file of H-alpha solar data

The SER files were stacked in Autostakkert!, wavelet processed in Registax and post processed in the Gimp 2.1.

Results

Ca K-line light

H-alpha light

The Ca K-line and H-alpha images were combined in Picture Window Pro 2.5 running in Wine, using translate, rotate and scale to exactly match the features on both images and to blend the images together.

H-alpha plus Ca K-line merged

Combining Calcium and H-alpha images in this way allows one to see the different types of structure revealed by each wavelength.

Jupiter and the Moon with AstroDMx Capture and an Altair GP-Cam 225C CMOS camera

A Skymax 127 Maksutov was mounted on an AVX mount and an Altair GP_CAM 225C CMOS camera was placed at the focus. For imaging Jupiter, the lens from a x2 Barlow was attached to the camera and for imaging the Moon, no Barlow was used.

AstroDMx Capture for Windows was used to capture the data. Stacking was done in Autostakkert!, wavelet processing was done in Registax and post processing was done in the Gimp 2.10.

Click on an image to get a closer view

Jupiter with Io shadow transit

Jupiter with the GRS and Io plus shadow transit

Screenshot of AstroDMx Capture capturing lunar data

Lunar images

The second image of each pair has been chrominance enhanced to reveal variation in the mineralogy of the lunar surface.

Plato, Sinus Iridum region

Herschel, Ptolemaeus region.

Copernicus, Kepler region

Archemedes, Aristillus region

Tycho, Clavius region

The Altair GP-CAM worked very well with AstroDMx Capture and works well on macOS, Linux, and 32bit Raspberry Pi Linux.

New feature release Version 1.0.5 of AstroDMx Capture and implementation of the Altair Hypercam 294C PRO 4GB TEC camera

New feature release of AstroDMx Capture with implementation of the 

Altair Hypercam 294C PRO 4GB TEC OSC CMOS camera.

Feature release of AstroDMx Capture for all platforms

Version 1.0.5

Mutatis Mutandis.

Nicola has released version 1.0.5 of AstroDMx Capture for Windows, macOS and Linux (including the Raspberry Pi) and Chrome OS.

Click on an image to get a closer view.

There are a number of significant changes in the new version

• Altair camera implementation. (The actual camera implemented was the Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera).
• Added: PNG output.
• Automatic white balance control (DMx Auto WB) independent of any camera specific white balance controls.
• Panning mode with scrollbars in hardware acceleration (drag-panning is still available)
• Thermal controls moved into their own control group.
• Improved cooling functions.
• Automatic selection for display performance.
• Sensor temperature in log and FITS metadata.
• Windows: changed colour of the control group titles.
• SVBONY and QHY SDK version increases.
• Automatic implementation of the correct version of AstroDMx Capture for Linux, based on the CPU and the version of the glibc dependency on the user’s computer. This removes the possibility of a user downloading the wrong version.
• Bug fixes.

DMx Auto WB

Some cameras such as the Atik 320E OSC CCD camera  and some others such as the Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, have a green cast to their images captured in RAW mode.

 Altair describes this as a natural result of using true RAW, and the green cast has to be removed in post processing.

AstroDMx Capture now has an option to apply an auto white balance (DMx Auto WB) in the preview AND the saved data when capturing from RAW data. DMX Auto WB can be turned on or off by the user.

The equipment used for the tests on DMx Auto WB. The camera used was an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera

The camera was kindly loaned to us by Dr Simon Helan of the Swansea Astronomical Society so that it could be implemented in AstroDMx Capture.

Screenshot of AstroDMx Capture for Windows preview of M27 with DMx Auto WB OFF with an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, a Skywatcher 130PDS f/5 Newtonian reflector mounted on a Celestron AVX GOTO EQ mount

It can be seen that there is a green cast to the preview image which is confirmed by the histogram.

Screenshot of AstroDMx Capture for Windows preview of M27 with DMx Auto WB ON with an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, a Skywatcher 130PDS f/5 Newtonian reflector mounted on a Celestron AVX GOTO EQ mount

It can be seen that with DMx WB ON there is now no green cast, which is confirmed by the histogram.

Final image of M27 with an Altair Hypercam 294C PRO 4GB TEC

Screenshot of AstroDMx Capture for Windows capturing data on M17 with DMx Auto WB OFF an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, a Skywatcher 130PDS f/5 Newtonian reflector mounted on a Celestron AVX GOTO EQ mount.

There is a strong green cast to the image which is confirmed by the histogram.

The brightness of the preview is due to the transform and other controls being applied to the preview. 

Screenshot of AstroDMx Capture for Windows capturing data on M17 with DMx Auto WB ON an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, a Skywatcher 130PDS f/5 Newtonian reflector mounted on a Celestron AVX GOTO EQ mount.

With DMx WB ON there is no green cast that is confirmed by the histogram.

The same transform and preview image controls are being used here as in the previous screenshot but DMx WB is ON.

Final image of M17 with an Altair Hypercam 294C PRO 4GB TEC

Screenshot of AstroDMx Capture for Windows capturing data on M16 with DMx Auto WB ON an Altair Hypercam 294C PRO 4GB TEC 14-bit CMOS camera, a Skywatcher 130PDS f/5 Newtonian reflector mounted on a Celestron AVX GOTO EQ mount.

Final image of M16 with an Altair Hypercam 294C PRO 4GB TEC

In a sense, it doesn’t matter whether the white balancing is done before or after capture, but a more pleasing and realistic preview of the image is obtained with the DMx Auto WB ON.

During post processing the removal of the green cast is no longer an issue and other aspects of the image can be concentrated on.

However, if live tracking and stacking was being done by using AstroDMx Capture with DSSL (Deep Sky Stacker Live), pre-capture white balancing would be essential for electronically assisted astronomical viewing, possibly for outreach and general appreciation of the accumulating stacked image. DMx Auto WB ON gives an altogether more satisfying imaging experience than when it is not used.

See my two x-bit blog articles for details on live stacking with AstroDMx Capture and DSSL.

Click on the link to see the full article

Setting up AstroDMx Capture for Windows and Deep Sky Stacker Live (DSSL) to work with each other.

Live deep sky image stacking with AstroDMx Capture for Windows and Deep-Sky Stacker Live.

With AstroDMx Capture now weighing in at more than 66 KLOCs of active code plus 11K lines of internal documentation over 5 operating system platforms, it has been an exhausting time for Nicola, bringing it to release Version 1.0.5.

Installing Wine, the Windows compatibility layer within the Crostini Linux environment on a Chromebook, and running Windows astronomy software

Installing Wine, the Windows compatibility layer within the Crostini Linux environment on a Chromebook.

There is software for Linux called Wine. This is software written for UNIX type operating systems that allows you to run many Windows programs under Linux. The name ‘Wine’ originally stood for ‘Windows Emulator’. However, its developers realised that this is a misnomer because no code emulation or virtualisation takes place when a Windows program runs in Wine. These days, the word ‘Wine’ is used as a recursive acronym that stands for ‘Wine Is Not an Emulator’. It is a Windows compatibility layer that allows Windows programs to run on a POSIX compliant operating system such as Linux. Unlike a virtual machine which emulates internal Windows logic, Wine translates Windows API calls into POSIX calls so that the Windows software runs under Linux without the performance and memory penalties inherent in emulation. Not all Windows programs run under Wine, but many of them do.

Installing wine on your Chromebook Linux is done in two simple stages:

First the installation of Wine.

Launch the Linux terminal and type sudo apt install wine

Then Press Enter.

A number of lines of text will appear in the terminal window and it will stop with a [Y/n] choice as to whether to proceed or not.

Type y

Then more lines of text will appear in the terminal and will continue until the process finishes and you get the prompt:

:~$

Second enabling the 32-bit wine libraries

Type into the terminal sudo dpkg --add-architecture i386

Then type sudo apt update

The type sudo apt install wine32

Several lines of text will appear in the terminal window and you will be presented with a [Y/n] choice as to whether to proceed.

Type y

Then more lines of text will appear in the terminal and will continue until the process finishes and you get the prompt:

:~$

Wine is now installed on your Chromebook and you will be able to run a number of Windows astronomy programs such as Registax 5.1, Autostakkert! 2 and Iris.

A few words about Windows programs

Windows programs fall into two categories:

First; those that install fully and their component files are scattered across various parts of the Windows system. Registax 5.1 is an example of this type of Windows program.

Second; those that do not install in the normal way. The executable and its dependencies are saved into a single folder. In Windows, the program is launched by double clicking on the executable. Autostakkert! 2 and Iris are examples of this type of Windows program.

Installing Registax 5.1

First download Registax to the Downloads folder and then copy it over to Linux files.

Launch the terminal and type ls at the :~$ prompt

This is a command to list the files in the directory (folder).

Somewhere in the directory you will see the name setupregistax5_1.exe

Because we are in the folder containing this file, we simply have to type at the :~$ prompt:

wine setupregistax5_1.exe

Registax will install exactly as it does in Windows, as you can see happening in the previous screenshot.

Once the installation has finished, Registax 5.1 will be available to use.

Launching Registax 5.1 (or any other program that installs normally).

This may seem a little daunting the first time you do it, but it will become second nature after you have used the terminal and command line a few times.

I will explain what is happening, step by step in this terminal session to launch Registax 5.1

Launch the terminal and type cd .wine at the :~$ prompt

This command tells the system to cd (change directory(folder) to the .wine folder).

The prompt has now changed to .wine$ because we are now in the .wine folder.

Type ls to list everything in the wine directory.

We can see that there are 5 items in the wine directory, and one of them is drive_c

Type cd drive_c to tell the system to change to the drive_c directory

The prompt has now changed to .wine/drive_c$

We now type ls to list everything in the drive_c directory

We can see that there are 5 items in the drive_c directory and one of them is the directory 

‘Program Files (x86)’.

Type cd ‘Program Files (x86)’ to tell the system to change to the ‘Program Files (x86)’ directory. The quote marks are essential when they are given.

The prompt has now changed to .wine/drive_c/Program Files (x86)$

Again we type ls to list everything that is in the ‘Program Files (x86)’ directory.

We can see that there are 5 items in the ‘Program Files (x86)’ directory and one of them is the directory ‘RegiStax 5_1’.

Type cd ‘RegiStax 5_1’ to tell the system to change to the ‘RegiStax 5_1’ directory.

The prompt has now changed to:

 .wine/drive_c/Program Files (x86)/RegiStax 5_1$

Then type ls to list everything in the ‘RegiStax 5_1’ directory.

We can see that there are 6 items in the ‘RegiStax 5_1’ directory, and that one of them is RegiStax5_1Final.exe.

To Launch Registax 5.1 simply type:

wine RegiStax5_1Final.exe

Registax 5.1 will then run as normal.

Preparing a program like Autostakkert!2 that doesn’t install like Registax.

The first thing to do is to download Autostakkert! 2 (or any other program that doesn’t have to install in order to be used; such a program is Iris)

AutoStakkert 2.6.8 is the version we have found to work and is downloaded as a zip file to the Downloads folder on your Chromebook.

In the Linux Files folder, right click and create a new folder and call it AutoStakkert2

Double click on the AutoStakkert 2.6.8 zip file in your Downloads folder. It will open up and show you four files. Click on each of the files to select them as shown below:

Right click on the selected files and select Copy.

Then open the Linux files folder and double click on the folder you created called AutoStakkert2.

When the folder opens, right click inside it and choose Paste. The 4 files for the AutoStakkert! 2 application will be copied into the folder.

AutoStakkert! 2 is now ready to use.

Launching AutoStakkert! 2

Open a terminal and type ls at the :~$ prompt, to list the items in the Linux files folder.

One of the items will be a folder (directory) called AutoStakkert2; this is the folder that you created, and into which you copied the AutoStakkert 2 files.

Type cd AutoStakkert2 to change directory to the AutoStakkert2 directory

The prompt will change to /AutoStakkert2$

Type ls to list the items in the AutoStakkert2 directory

There will be six items in the directory and one of them is the executable

AutoStakkert.exe

Type wine AutoStakkert.exe

And AutoStakkert2 will launch

Practice launching Registax and AutoStakkert a few times and it will become second nature.

A few words about using the terminal and the command line.

It may seem a little daunting to use the terminal and the command line, but it shouldn’t be. Early personal computers in the 1980’s used operating systems such as DOS and CPM. Ordinary home users of these computers only had the command line with which to get anything done. There was no such thing as Windows and GUIs but the users of these operating systems found no difficulty in using them.

Modern users of Linux, macOS and Windows all have a terminal and command line that they can use, but for most people it is not necessary, and many are even unaware of their existence. Linux users are more likely to use the terminal and command line on a regular basis, but even for them, it is not essential.

The Chromebook is a Linux machine inside which is another Linux virtual machine, Crostini, that we are using here. It is a simple matter to get our programs launched from the terminal and command line, all it takes is a little practice.

The computer is pedantic and requires everything to be typed in correctly. If quotes are required, they must be there; the case of letters matters and spaces are important where required. If you find that anything doesn't work, it is because you have made a mistake in your typing. To have another go at a line which has just failed, just press the UP cursor key and the line will re-appear as you typed it; just examine it carefully to find the typing error you have possibly made. Correct the error and press Enter. It will now execute correctly.

Installing Linux on a Chromebook, installing and running Linux applications, including AstroDMx Capture for Chrome OS Linux

When you have Linux installed on your Chromebook, you will be able to install locally a number of programs and greatly enhance the functionality of the Chromebook, and also enable it to be used for astronomical imaging with the SVBONY, SV305, SV305 Pro and SV305M Pro cameras; the only astronomy cameras that will work with Chrome OS Crostini at the moment.

Versions of Chrome OS of 91 and above are able to set up Linux in the stable channel and require no special preparations to do so.

Click on any image to get a closer view

Follow these steps to set up Linux on your Chromebook

In your Chromebook, click on the time at the bottom right of the screen

Select Settings, 

then Advanced, then Developers.

By the ‘Linux development environment’, select Turn on.

Just follow the on-screen instructions and after a few minutes, a Terminal window opens.

The Debian 10 Linux is now installed and you can run Linux commands in this terminal.

Updating the Linux environment

You will notice that the first line of the terminal contains your username followed by the prompt

:~$

So the prompt will always look something like this:

joebloggs@penguin:~$

Where joebloggs is your username (of course, yours will be something different).

The first commands to type into the terminal are to update the Linux you have just installed

Type in sudo apt update and press Enter.

When you press Enter something like this will be printed in the terminal window:

In my system, shown above, everything is up to date. However, yours probably won't be.

Then at the :~$ prompt as shown above, type: sudo apt upgrade and press Enter.

Again, in my system, everything is up to date.

If however, there were any packages that needed to be updated, you would be given the option [Y/n] as to whether to proceed. You type y to proceed with the upgrade.

You now have a fully functioning Linux virtual machine within your Chromebook and you can download and install Linux applications to run in it.

Installing two Linux applications

The first application that we will download and install is AstroDMx Capture for Chrome OS Linux. This is downloaded from the AstroDMx Capture website and is downloaded as a .deb file.

The AstroDMx Capture website is at https://www.astrodmx-capture.org.uk/

When you download the .deb install file it will be downloaded to the Downloads folder in Files on your Chromebook.

Install the AstroDMx Capture .deb file as shown below:

Right click on the file and select Install with Linux

After a few moments, the details of the file will be shown in a dialogue box.

Click on Install.

A small information box appears at the bottom right of the screen to inform you that installation is underway.

When the installation is complete, the AstroDMx Capture icon will appear in your programs just like any other application.

Clicking on the AstroDMx Capture icon will launch AstroDMx Capture. It would be a good idea to right click on the icon and select Pin to shelf. In this way. AstroDMx Capture will always be immediately available to launch.

Other .deb files for other applications can be downloaded from websites and installed in exactly the same way. However, it should not be necessary to go searching for the applications that you want, as they should be available in the Debian repository.

These are the Linux applications that I have installed and grouped together in the Programs window.

I will explain how to install one of them, SER Player. All of them can be installed in the same way.

Type into the terminal window after the :~$ prompt

sudo apt install ser-player

Some lines of text will appear in the terminal window finishing with a question:

Do you want to continue? [Y/n]

Type in y

Then SER Player will begin to install:

When SER Player is installed you will be returned to the :~$ prompt

SER Player is now installed and is available to use.

Running AstroDMx Capture

Just click on the AstroDMx Capture icon and the application will launch:

To get started with AstroDMx Capture, read the article HERE.

Running SER Player

Just Click on the SER Player icon and the application will launch:

This application will enable you to view and even process SER files if required.